Meanwhile, the dollar slumped overnight against a basket of major currencies on Thursday, weighed by a surge in the euro to six-month highs, as viewers' polls declared that Emmanuel Macron won a TV presidential debate against Marine Le Pen, increasing the likelihood of a Macron victory at the runoff vote on Sunday.

The US dollar index, which measures the greenback's strength against a trade-weighted basket of six major currencies, rose 0.09 percent to 98.70.